E.i. Dupont De Nemours and Company

Other

David M Harriss

Robert Byron Bruce

Steven R Allen

Stasys K Rudys

David Jackson McGinty

The present invention relates to a fungus resistant gypsum board, made of first and second polymeric fibrous sheets with a gypsum core sandwiched there between. The gypsum core containing less than 0.03% of formulation additives that serve as fungus nutrients and less than 0.5% of the dry gypsum core contains of fungus nutrients. The fibrous sheets are preferably nonwovens and the gypsum core preferably contains a fungicide. The invention is also directed to a process for making a fungus resistant gypsum board.

Fungus resistant gypsum-based substrate

The present invention relates to a process for manufacturing a gypsum-based substrate. The process includes the steps mixing gypsum and water to produce a gypsum slurry, providing a synthetic polymeric fibrous sheet on one side of a layer of the gypsum slurry, and adhering to the wet gypsum to the sheet with an adhesive strength of at least 7.5 lb. The present invention is also directed to a gypsum board comprised of first and second polymeric fibrous sheets adhered to opposite sides of a wet gypsum core, wherein the first surface of the first sheet and the first surface of the second sheet have pores containing set gypsum and the first and second sheets adhere to said wet gypsum core with an adhesive strength of at least 7.5 lb.

Gypsum-based construction material

Improved sheets of bonded plexifilamentary film-fibril strands spun from a polyolefin and a pigment are provided. The polyolefin comprises at least 90% by weight of the fibril strands, and the pigment comprises between 0.05% and 10% by weight of the fibril strands. The sheet has a high opacity and high smoothness, even when the sheet is bonded to a delamination strength greater than 120 N/m or when subjected to calendering. The sheet material is highly printable.

Flash-spun sheet material

A process for making a PPD-T fiber having an elongation to break of greater than 7%.

Growing community of inventors

Chesterfield, VA, United States of America

David M Harriss